These Disposable Ultra Fine Filters are made of Polyester fibers in a light blue carrier.

USAGE: These filters are disposable and should be replaced after 30 nights of use or sooner if they appear dirty. To install an ultra fine filter in your DreamStation, slide the blue foam pollen filter out of the machine, securely snap the light blue ultra fine filter onto the base of the foam pollen filter, and insert them both back into the device.